Underreamer



Nov. 28, 1961 M. G. SCHUTTE ETAL 7 UNDERREAMER Filed May 27, 1957 8 Sheets-Sheet 3 Norman L. \Sc/w He INVENTORS Mf/(M- A TTORNE YS Nov. 28, 1961 M. 5. SCHUTTE ETAL 3,010,527

UNDERREAMER 8 Sheets-Sheet 6 Filed May 27, 1957 My/e: G. Jcbuffe Nor/7700 L Jcfiuffe INVENTORS ATTOR/VEVJ United States Patent 3,010,527 UNDERREAMER Myles G. Schutte and Norman L. Schutte, both Bell Bottom Foundation Company, 4655 Telephone Road, Houston, Tex.

Filed May 27, 1957, Ser. No. 661,885 23 Claims. (Cl. 175286) This invention relates to an underrearner and more particularly to a tool for enlarging the lower ends of holes in the earth to form enlarged portions for receiving concrete in the construction of foundation work.

This application is a continuation-in-part of co-tpending US. patent application, Serial No. 338,936, filed February 26, 1953.

An important object of this invention is the provision of an underreamer which may be lowered in a retracted condition in a previously formed hole and which may be rotated and expanded to enlarge and underream the hole.

Another object of the invention is to provide an underreamer of the type referred to which takes the form of a receptacle or earth container and which embodies cutting means which also function as closures for the receptacle to retain the earth therein for removal from the hole.

A further object of the invention is the provision of an underreamer having a rotatably supported cylindrical body formed with earth receiving openings and closures hinged to the body and provided with cutters which are operable upon opening of the closures and rotation of the body to cut away the earth in a hole surrounding the body, the closures being also operable to close the opening to retain the earth in the body for removal from the hole.

Another object of the invention is the provision of an underreamer which is constructed to receive and retain a relatively large amount of the cut-away material and from which the material may be easily and quickly dumped.

A still further object of the invention is to provide an underreamer of simple design and rugged construction capable of long withstanding the rough handling and extreme conditions of hard usage to which such equipment is customarily subjected.

Another object of this invention is to provide an underreamer wherein all of the weight which is applied to the underreamer for reaming purposes is applied directly to the cutters on the underreamers, whereby maximum reaming action is obtained.

A particular object of this invention is to provide an uuderrearner which has means therewith for reaming an annular substantially vertical wall portion at the bottom of the hole which is underrearned with the underreamer, said means being so constructed that said wall portion is cut substantially vertically throughout the entire underreaming operation.

Still another object of this invention is to provide an underreamer which has a first cutter means for providing the main portion of the underrearning in a hole and a. second cutter portion :Eor providing a substantially vertical lower annular wall in the enlarged part of the hole so that upon the subsequent pouring of concrete in said hole, a sharp annular edge at the bottom of the enlarged part of the hole is prevented, whereby the danger of cracking and chipping the concrete in the enlarged part of the hole is reduced or prevented.

The above and other important objects and advantages of the invention will best be understood from the following detailed description constituting a specification of the same, when considered in conjunction with the annexed drawings, wherein- FIG. 1 is a vertical, central, cross-sectional view of the invention, showing the same in closed condition;

3,010,527 Patented Nov. 28, 1961 FIG. 2 is a side elevational view of the invention in closed condition;

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 2, looking in the direction indicated by the arrows;

FIG. 4 is a vertical, central, cross-sectional view of the invention, showing the same in its fully extended condition in a hole and illustrating the manner in which the tool is operated;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 4, looking in the direction indicated by the arrows;

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 4, looking in the direction indicated by the arrows;

FIG. 7 is a side elevational view of the invention illus-' trating the manner in which the same is operated to Lu1- load the device; 7

FIG. 8 is a cross-sectional view taken on line 8-8 of FIG. 1;

FIG. 9 is a vertical sectional view taken on line 9-9 of FIG. 1',

FIG. 10 is a vertical sectional view of a modified form of the invention in the closed position; 7

FIG. 11 is a cross-sectional view takon on line 11-11 of FIG. 10;

FIG. 12 is a vertical sectional view taken on line 12-12 of FIG. 10;

FIG. 13 is a cross-sectional view taken on line 1313 Of FIG. 12;

FIG. 14 is a vertical sectional view of the form shown in FIG. 10, but illustrating such device in the extended position it assumes at or near the completion of the un' derream-ing of a hole;

FIG. 15 is vertical sectional view showing a portion of the form of the device of FIG. 13 in a dumping position; and

FIG. 16 is a partial sectional view illustrating a modified latch means for the lower dumping plates.

Referring now to the drawings in greater detall, the underreamer has a body 10 of which is preferably cylindrical form and which has oppositely disposed longi tudinally elongated openings 12, 12 therein. The bottom of the body is formed by a pair of semi-circular drop doors 14, 1'4 hingedly secured on a horizontal, centrally located shaft 16 secured at its opposite ends to the body.

The top of the body It) may be closed by a top plate 18 having a central opening 18a therein, through which a tubular guide member 20 or drive member having an opening with polyganal sides extends, said member having an outwardly extending annular flange 22 at its upper end which overlies and is secured to the .top plate 18 about the opening 18a in any suitable manner as by the bolts 24. The tubular member 20 is preferably of square or angular cross-section and is provided with a plurality of surfaces or sides which define the opening of the member 20, and an operating shaft 26 of corresponding cross-sectional shape and preferably with the same number of surfaces or sides as the member 20 extends through the member 20 and is slidable therein. An inner plate 19 extends across the interior of the body in downwardly spaced relation to the top plate 18 and has a central opening 25 therein surrounded by an upstanding annular wall 27, which carries at its upper end a plate 29, having a central opening 1 through which the tubular guide member 20 extends downwardly and which forms with said annular wall 27 a downwardly opening recess 21 into which the tubular guide member 20 opens at its lower end.

Within the body there is a cross head 28, which in the present illustration is of plate-like construction, having 3 oppositely disposed, outwardly extending, vertical flanges 30, 30 which are slidably received in vertical guideways 32, 32 secured to the inside of the body. Stop member 33 is provided in the guideways, as seen in FIG. 2, with which the flanges 30 are engageable to limit downward movement of the cross-head. Arcuate doors or closure elements 34, 34 are pivotally secured at their upper ends to opposite sides of the cross-head 28 by hinges 36, 36. Each hinge 36 (-FIG. 2) includes spaced lugs 36a which extend from the cross-head or plate 28 (FIG. and which inter' fit between spaced lugs 36b which extend from each closure element 34; a pivot or hinge pin 36c (FIG. 1) extends through aligned openings in the lugs 36a and 36b for each element 34. The elements 34 are thus adapted to pivot to open and close the openings 12, and at their lower ends these doors are formed with vertically disposed lower cutter portions 38, 38, hingedly secured thereto by hinges 39, 39 and adapted to overlie the outer marginal portions of the drop doors 14, 14, when the closure elements 34, 34 are in closed positions, as

7 best seen in FIGS. 1 and 2. The lower cutter portions 38, 38 operate to form a vertical walled portion or toe in the enlarged portion of the hole at the completion of the reaming operation as illustrated in FIG. 4 of V the drawings, and as will be more fully explained hereinafter.

Each of the vertically disposed lower cutter portions 38, 38, has a lug 94 on its inner side to which the lower end of a link 96 is pivotally connected, and this link extends upwardly for pivotal attachment at its upper end to a lug 98 extending downwardly from the cross-head 28 so that the lower cutter portions 38 are held in vertical positions in all positions of the closure members 34, 34, as will be explained more in detail.

The vertical guideways 32, 32 are each provided with a stop member 33, as best seen in FIG. 2, which members are positioned to be engaged by the lugs 30, 30 (FIG. 9) of the cross-head 28 to limit downward movement of the cross-head 28 in the guideways 32, 32. A stop element 35 is also carried by the cross-head 28, attached to the lower ends of vertical supports 37 on the crosshead, which stop element 35 (as best seen in FIGS. 5, 7 and 9) is located beneath the lower end of the operating shaft 26 and is engageable therewith to limit down- Ward movement of the shaft relative to the cross-head 28, thus limiting outward movement of the closure members 34. .The shaft 26 passes through a central Opening 40 in the cross-head 28, so that the shaft 26 and the crosshead 28are independently movable.

Oppositely extending connecting rods 42, 42 are pivotally connected at their inner ends to pivot pins or bolts 44, to the lower end of the operating shaft 26, and at their outer ends these rods are pivotally attached to inwardly extending lugs 46, 46 on the closure elements 34, 34 mediate the ends of the elements, so that upon raising of the shaft 26 relative to the body 10, the closure elements or doors will be drawn inwardly to closed positions, as shown in FIGS. 1 and 2, and upon downward movement of the shart relative to the body the doors will be extended outwardly from the body about the hinges 36, 36 as seen in FIGS. 4 and 7.

The connecting rods 42, 42 are formed or provided with downwardly directed lugs 48, 48 near their outer ends, and link elements 50, 50 having elongated slots 52, 52 at their upper ends are hingedly connected to the lugs 48, 48 through these slots, as best illustrated in FIG. 1. The link elements 50, 50 are pivotally connected at their lower ends to the horizontal shaft 16 upon which the drop doors 14, 14 are hinged. The connecting rods 42, 42 are provided with lugs 54, 54 near their inner ends. Each of the door operating chains 56, 56 has one end connected to a lug 54 and the other end connected to one of the lugs 58, 58 on the drop doors 14, 14. By this construction the closure members 34, 34 may move to open or closed positions by manipulation of the operating shaft 26, and upon closing movement of the closures the drop doors will be securely held in closed condition.

The closure elements or cutting members 34, 34 are each provided with a series of cutting blades 60 bolted thereto to form a cutting means or assembly. The blades of one cutting member 34 are offset longitudinally with respect to the blades of the other cutting member 34 (as seen in FIGS. 1, 4 and 7), so that the annular areas cut by the blades 68* on one member 34 are in between the annular areas cut by the blades 60 on the other member 34 as such members 34 are rotated, whereby it is unnecessary to provide cutters or blades 60 for the full length of each member 34 in order to cut or ream out the full annular area of the hole for substantially the full length of the members 34, 34. All of the blades 60 have their cutting edges directed in the same direction circumferentially of the body .10, so that upon rotation of the reamer body 10, the cutter members 34 are rotated with the blades 60 to cause the blades 60 to cut away the surrounding wall of the bore hole'throughout the entire length of the members 34. The blades 60 are bolted on the insides of the closures and extend outwardly through openings 62 therein, the blades extending only partly across the openings (as shown in FIG. 3), so that the material such as rock and earth which is cut away by the blades may pass freely through the openings 62. The cutting edges of the'blades may be coated or otherwise formed with hardened, wear-resisting alloy or other material.

Cutting blades 61 and similarly to the blades openings 63 which are arranged 60 and the openings 62 are also provided on the lower cutter portions 38, 38. The cutting blades 60 and 61 are preferably formed with cutting edges at both ends and are shaped to be reversed and provided with two holes as best seen in FIG. 3, whereby the blades may be reversed when worn.

Within the openings 12 vertically disposed scoop elements 82, 82 are hingedly attached at one end to the interior of the body for inward and outward horizontal swinging movement through the openings. These scoop elements are curved or bent as seen at 86, 86 in the direction of the rotation of the body, so that they tend to engage and guide the earth, rocks and other cut away material into the interior of the body during the cutting operation. Each of the cutter portions 38 has an inside lug attached thereto, which extends over the free end of the corresponding scoop element 82, so that upon outward movement of the closure members the scoop elements are moved outwardly, and readily move to their extended positions, as seen in FIG. 6, when the body 10 is rotated in a direction (clockwise as viewed in FIG. 6) to enlange the here or hole H to provide the enlarged underreamed portion E (FIGS. 4 and 6).

Beneath the top plate 18, the body 10 is provided with oppositely disposed openings 68, 68 for the reception of hooks 70, 70 pivotally carried on a suitable supporting structure 72 (FIG. 7), whereby the body may be supported to permit dumping of its contents by downward movement of the operating shaft 26, as shown in FIG. 7. The hooks 70 are preferably but not necessarily counterweighted as indicated at 74, 74 and have sloping surfaces 76, 76 engageable with the body upon upward movement of the body to cause the hooks to spread apart and enter the openings 68, 68 to suspend the body from the support. Suitable securing means, such as the downwardly extending plates 78, 78 are attached to the support 72, which plates are provided with a number of spaced openings 80, whereby the books may be pivotally connected to the plates at differently spaced points to accommodate ditferent sizes of reamer bodies. The supporting structure 72 will usually be a part of suitable hoisting mechanism, such as a crane which may be used to elevate and lower the reamer and move the same to some convenient location for dumping its contents.

In the use of the form of the invention of FIGS. 1-9,

the reamer is supported by the operating shaft 26, in the closed condition shown in FIGS. 1 and 2, and lowered into a bore hole H (FIG. 4) which is previously formed and which is preferably only slightly larger in diameter than the outer diameter of the body of the reamer. The reamer is thus lowered until it rests on the bottom B (FIG. 4) of the hole H, whereupon the operating shaft 26 is rotated to cause the body 10 and the parts connected therewith to rotate in the hole, and at the same time the shaft 26 is lowered by applying weight thereto at the ground level above the hole H to move the closure elements or cutter members 34, 34 outwardly toward open position. The cutting blades 60 are thus caused to engage the adjacent portions of the wall of the hole to cut the same away to form the enlarged underreamed portion E as the reamer is rotated.

The drop doors 14 rest on the bottom 13 and provide a base or support on the bottom B which prevents the doors 14, the body 10, and the links 50 from moving downwardly as the operating shaft 26 is lowered downwardly. Since the link elements 59 are pivotally connected from the doors 14 to the rods 42, the downward force which is transmitted from the shaft 26 to the rods 42 does not cause the rods 42 to move downwardly except to the limited extent permitted by the pivoting of each of the rods 42 about its pivotal connection to the lug 46 as each rod 42 moves from the inclined position of FIG. 1 at the start of the underreaming to the substantially horizontal position of FIG. 4 at the end of the underreaming. Because the links 42 are thus limited in their downward movement, the downward force imparted to the links 42 from the operating shaft 26 is almost entirely converted into lateral or substantially horizontal movement at the lugs 46 on the cutter members 3-1, so that the weight or force on the shaft 26 is transmitted to the intermediate portion of such cutter members 34 through rods 42. As the cutter members 34 are thus urged laterally outwardly from the body 10 by the force transmitted thereto from the operating shaft 26 through the rods 42, such cutter members 34 pivot at their upper ends about their hinge pins 360 so that the members 34 swing outwardly at their lower ends about their hinges 36. As the lower ends of the members 34 move outwardly in a substantially horizontal plane, the plate or cross-head 28 moves downwardly relative to the body 10 and doors 14 from the starting position (FIG. 1) to the final posit-ion (FIG. 4). It will be appreciated that during such outward swinging of the members 34, the operating shaft 26 is rotated by a suitable drive means such as a conventional rotary table (not shown) which is located at the ground level above the hole H, whereby an enlargement E is formed which is substantially frusto-conical from the bottom of the cutters 34 to approximately half-way up to the cutters 34 and is tapered outwardly concave thereabove.

The lower cutters 38 remain substantially vertical throughout the outward swinging or pivoting of the upper cutter members 34 from the initial or starting position (FIG. 1) to the final position (FIG. 4) so that regardless of the extent of the underreaming provided with the elements 34, the lower annular wall or toe T of the enlargement E is substantially vertical. The links Q6 connected from the cutters 38 to the cross-head or plate 28 control the movement of cutters 38 so as to maintain the cutters 38 substantially vertical throughout their travel from their closed or retracted position (FIG. 1) at the start of the underreaming operation to their extended or final position (FIG. 4) at the end of the underreaming operation. In order to accomplish the maintenance of the cutters 38 in their substantially vertical positions, the movement of each of the links 95 must hear such a relationship to the movement of the cutter members 34 that the lugs 94 at the lower ends of the links 95 remain in the same position relative to the hinges 39 throughout the reaming operation. In other words, if the links 96 permits the lugs 94 to swing either inwardly or outwardly relative to the hinges 39 during the reaming operation, it will be evident that the cutters 38 will swing away from its vertical starting position and therefore would not continue to cut the wall T vertically. Since the upper ends of the links 96 and the upper ends of the cutters 34 are both connected to the cross-head 28 at the lugs 98 and the hinges 36, respectively, the lugs 98 and the hinges 36 are both moved downwardly together but without any lateral movement during the reaming operation. On the other hand, the lugs 94 and the hinges 39 move laterally or horizontally but without any vertical or downward movement during the reaming operation. Therefore, all of the downward or vertical travel of the hinges 36 and lugs 98 is converted into lateral or horizontal movement of the lugs 94 and the hinges 39. With each of the links 96 mounted in a position parallel to an imaginary straight line running between the hinges 36 and 33 on each cutter member 34-, and with an imaginary line from hinge 39 to the lower pivot of link 96 also parallel to an imaginary line from hinge 36 to the pivot at the upper end of the link 96, so that the hinges 36 and 39 and the upper and lower pivots of link 96 are at the corners of an imaginary parallelogram, it is assured that the lugs 94 will move the same amount laterally or horizontally as the hinges 39 so that the cutters 38 remain substantially vertical throughout their full lateral travel during the reaming operation. The formation of the vertical annular wall T is important because when concrete is poured into the hole H to fill the enlargement B after the reamer is removed a base layer is provided with the wall T at the outer annular vertical surface so that the formation of a sharp annular edge on the concrete at the bottom of the inclined walls E is prevented. Such a sharp annular edge is formed with conventional underreamers and it is very detrimental because such edge is particularly subject to chipping off and cracking which naturally reduces the strength of the concrete. The present invention eliminates such defect.

During the reaming operation, as the entire reamer is rotated, the earth, rocks and other material which is cut away by the blades 60 will pass through the openings 62 and be deposited at the bottom B of the hole as the same is gradually enlarged. Since the drop doors 14 are maintained in the closed position (FIG. 4) by engagement with the bottom B of the hole some of the arth, rocks and other material collects on the upper surface of each drop door 1.4. e

When a certain amount of the cut away material has been deposited, the rotation of the reamer is arrested and an upward pull is taken on the operating shaft 26, whereupon the closure or cutter elements 34 are drawn inwardly by the connecting rods 42 and engage the scoops 82 and move these elements inwardly to move the deposited material on the bottom l3 onto the drop doors 14. A relatively large quantity of loose deposited material is thus compressed into the body and retained therein for removal from the hole. The reamer is then lifted out of the hole by upward movement of the operating shaft 26, and moved into engagement with the hooks 7 0, to cause the hooks to enter the openings 68, to support the reamer from the supporting structure 72. By then moving the supporting structure 72 to any desired location the contents of the reamer may be dumped by downward movement of the operating shaft 26, which causes the closure elements 34 to move outwardly, and allows the drop doors 14 to swing downwardly, as shown in in FIG. 7. Should the contents of the body become tightly packed therein, so that the material does not readily fall out as the doors 1 swing open, the material will be forced out under the influence of the downward pressure exerted thereon by the cross-head 23.

After the material has been dumped from the body the reamer may be closed and again moved over the hole H, whereupon it may be readily released from the supporting structure 72 by rotating the body so that the books 70 ride out of the openings 68, and to more readily accomplish the release of the body the weight of the same may be removed from the hooks by an upward pull on the operating shaft before such rotation. Of course, the hooks 70 may be moved out of the openings 68 by any other procedure.

in FIGS. -14, a modified construction of the reamer of this invention is illustrated. The parts of the form of the invention illustrated in FIGS. 10-14 which are identical with those illustrated in FIGS. l-9 have like numerals, but the modified portions of the form of the reamer shown in FIGS. 10-14 which diiier from the parts shown in FIGS. 1-9 have different numerals as explained and identified hereinafter.

The body 10 of the reamer of FIGS. 10-14 is substantially the same as the body 10 of FEGS. l-9, except that the upper end thereof, including the top plates 11S and 119 have been modified. Thus, the body 10 is axially formed with arcuate or curved sections 19a and 19b (FIG. 11) which, together with the arcuate or curved closure or cutter members 34, form the substantially cylindrical body 10 of the reamer. The closure or cutter members 34 are mounted for movement in the same manner as previously described and they fit into the openings 12 of the body 10 which are provided between the arcuate body sections 10a and 10b. The modified plate 119 is positioned just above the openings 12 and the upper ends of the members 34. Such plate 119 is annular and is welded or otherwise secured to the arcuate body sections 10a and 10b, and it is likewise welded at the lower end of the ring portion 190 of the body 11 which is formed at the upper end of the body 10. The annular disk or plate 119 is substantially the same size and shape as the upper annular plate or disk 118 which is welded or otherwise connected to the upper surface or edge of the ring portion 100 of the body 10. The 1 plates 118 and 119 have central openings 118a and 119a, respectively which are preferably longitudinally aligned to provide an opening through which the operating shaft 26 is adapted to extend. Also, the cross-head or plate 28 carries a tubular member 120 and a supporting structure therefor which extends into the opening 119a in the plate 119. The tubular member 120 corresponds with the tubular member 26 of FIGS. 19 and is preferably of square or angular cross-section so that it corresponds with the square or angular cross-section of the operating shaft 26, whereby rotation is transmitted from the operating shaft 26 to the tubular member 126 so that such member 120 serves as a Kelly connection. The tubular member 120 may have an annular flange 122 formed thereon if desired. The lower portion of the Kelly member 120 is welded or otherwise secured to an annular plate 129, which in turn is welded or otherwise secured to a vertically extending ring 127 which has a laterally extending annular flange 127a formed therebelow. The plate 129, the ring 127 and its flange 127a together form the supporting structure for the tubular member 12% and such supporting structure isbolted or otherwise connected to the plate 28 by suitable connecting means such as bolts 124'.

As previously explained in connection with FIGS. 1-9, the cross-head or plate 28 is annular in construction and has a central opening formed therein through which the operating shaft 26 and the upper ends of the links 42 are adapted to extend. The plate or head 28 is a movable plate which in effect floats downwardly as the cutter members 34 pivot outwardly during the reaming operation. The upward movement of the plate 28 is limited by its contact with the stop plate 119 (FIG. 10). The plate 28 has stop lugs 30 formed thereon (FIG. 12) which engage an adjustable stop bar 133 to limit the extent of the downward movement of the cross-head or plate 28. The lugs 30 move in channels 132a which are provided between spaced guide plates 132 (FIGS. 10 and 12). The guide plates 132 are formed with a plurality of openings 132b so that the bolts 133a can be positioned at different levels for changing the position of the stop bars 133. By adjusting the position of the stop bar 133, the limit of the downward travel of the cross-head or plate 28 is changed to vary the amount of outward movement of the cutter members 34 to thereby control the size of the underreaming of the enlarged portion E of the hole H. With such construction for limiting the downward travel of the crosshead 28 and for thereby limiting the outward extent of travel of the cutter members 34, the stop bar 35 and its supports 37 used in FIGS. 1-9 are eliminated in the form of the invention shown in FIGS. 10-14.

The hinges 36 and 39 with the cutter members 34 and 38 are identical with those disclosed in connection with FIGS. 19. Likewise, the links 96 which extend from the lugs 98 to the lugs 94 are identical with those disclosed in connection with FIGS. 1-9. It will be noted that the link 96 is shown in FIG. 10 as parallel with an imaginary line which extends from the hinge 36 to the hinge 39 in connection with each of the cutter members 34. It will also be noted in FIG. 14 that when the cutter members 34 are moved to their extended position the links 96 are still parallel with the imaginary lines extending from the hinges 36 to the hinges 39, and such would be the case regardless of the position of the cutter members 34.

The links 42 are identical with those disclosed in connection with FIGS. l9 except that the lugs 54 have been omitted because the chains 56 are omitted. The links 50 are identical with the links 50 of FIGS. 1-9 and preferably include the slots 52 at their pivotal connection with the lugs 48 on the rods or links 42. The lower ends of the rods 50 have sleeves 50a formed thereon or welded thereto through which the hinge pin 16 extends. Such hinge pin 16 extends from one of the arcuate body portions 10a to the other body portion 10b as best seen in FIG. 11 so as to mount the drop doors 14 for pivotal movement on such hinge pin 16. Thus, the left drop door 14 as seen in FIG. 11 has hinge sleeves 14a formed thereon or welded thereto through which the hinge pin 16 extends to permit pivotal movement of the drop door 14 about the hinge pin 16. Similarly, the right drop door 14 as viewed in FIG. 11 has hinge sleeves 14b through which the hinge pin 16 extends to permit the pivotal movement of the right door 14 about the pin 16; The doors 14 are ordinarily prevented from falling downwardly and are therefore maintained in the substantially horizontal position shown in FIG. 10 during the lowering of the reamer into a hole H by means of the engagement of the edge 156a of a curved stop plate 156 with the edge 158a of a stop plate 158. The stop plate 158 is welded or otherwise secured to the lower surface of one of the drop doors 14 and the curved stop plate 156 is welded or otherwise secured to one of the links 50 and it extends around the lower side of the hinge sleeve 50a therewith. The other link 50 has a similar curved stop or latch plate 154 welded or otherwise secured to its hinge sleeve 50a so that the edge 154:: contacts the edge 155a of a stop plate 155 on the bottom of the other drop door 14. Thus, the coaction between the plates 156 and 158 and the plates 154 and 155 latches the drop doors 14 in the closed position during the normal lowering of the reamer into the hole H. Such latching effect is believed evident from FIG. 10 wherein it can be seen that the drop doors 14 are prevented from moving downwardly because of the co-action or engagement of the surfaces 156a and 158a and also the surfaces 154a and 155a. However, when the links or rods 50 are moved downwardly so that the surfaces 156a and 1580 are moved away from each other and the surfaces 154a and 155a are moved away from each other, as will be more fully explained in connection with FIG. 14, then the doors 14 are permitted to drop by gravity or by the weight of the material which is collected thereon during the reaming operation. It will thus be appreciated that the latch or stop plates 156 and 158 and the stop or 9 latch plates 154 and 155 take the place of the chains 56 in FIGS. 1-9.

It should be noted that the scoop elements 82 which are shown in FIGS. 19 have been omitted from FIGS. 10l4, but of course, such scoop elements 82 could be included with the form of the invention shown in FIGS. l-l4 if so desired. It will be understood that the cutter blades 69 and 61 and the other parts which are not specifically mentioned in connection with FIGS. -14 are identical with those disclosed in connection with FIGS. 1-9.

The operation or use of the form of the invention disclosed in FIGS. 10-14 is believed evident from the foregoing description. Actually, the operation and use of the form of the invention shown in FIGS. 10-14 is substantially the same as disclosed in connection with FIGS. 19. Thus, tne entire reamer is lowered into a hole H which has been previously drilled with any suitable drilling equipment (not shown) During such lowering of the reamer, it is in the closed or starting position illustrated in FIGS. l012. When the bottom plates 14 contact the bottom B (FIG. 13) of the hole H, the downward movement of the reamer in the hole H is stopped. The application of weight to the operating shaft 26 and the rotation of such shaft 26 at the ground level above the hole H is then commenced to cause the rods or links 42 to be forced outwardly for moving the cutter or closure members 34 outwardly about their hinges 36 for reaming the enlarged frusto-conical hole portion E (FIG. 13). As previously pointed out in connection with FIGS. l9, the contact of the bottom plates 14 on the bottom B of the hole I-I prevents the rods or links 50 from moving downwardly so that such rods or links 42 are forced outwardly to the position shown in FIG. 13 upon the application of the weight or force to such rods 42 through the operating shaft 26. The lower cutter members 38 move outwardly with the upper cutter members 34 and, as explained previously in detail, such lower cutter members 38 remain substantially vertical throughout their travel from their starting position (FIG. 10) to the final position (FIG. 13). In fact, the size of the enlarged portion E can be varied by adjusting the place at which the stop member 133 is located, as previously explained, and therefore it is important for the lower cutter elements 38 to be vertical, or substantially vertical, at all points of travel during the reaming operation because regardless of the size of the underreamed portion E, it is important to have the toe or vertical wall T vertical or substantially vertical so that a base will be provided which will not crack or chip as mentioned in connection with FIGS. l-9. It should be noted that in FIGS. 10-14 the kelly or drive sleeve 124 moves downwardly with the cross-head or plate 28 so that the lower end of the shaft 26 does not move very far from such kelly 120 and therefore greater support against wobbling and vibration is provided by the kelly sleeve 120.

The dirt, rocks or other material which is cut away from the hole during the underreaming operation falls into the area inside of the cutter elements 34, and it is accumulated on the bottom B or on the top of the doors 14. When a sufficient quantity of dirt has accumulated, or when the enlargement E has been drilled to the desired size, the shaft 26 is raised to draw or swing the cutter elements 34 and the cutter elements 38 inwardly towards the closed position. During such movement inwardly, the dirt on the bottom B is pushed onto the doors 14 and is therefore confined within the area defined by the housing 10 in its closed position (FIG. 10). If the scoops 82 illustrated in FIGS. l-9 are utilized, an increased amount of the dirt may be collected. In any event, the reamer is withdrawn from the hole H (FIG. 13) when it is in the retracted position of FIG. 10 and it has a load of dirt confined therein. The dirt is dumped by engaging the hooks 70 of FIG. 7, or any similar hook mechanism within the openings 68 (FIG. 10). Then, the body 10 is held against downward movement and the shaft 26 is lowered. Such lowering of the operating shaft 26 while holding the body 10 against downward movement causes the rods 42 to move downwardly for swinging the elements 34 outward ly. As the elements 34 swing outwardly, the rods or links 50 swing downwardly to the position shown in FIG. 14 so that the ends or edges 156a and 154a move towards each other to permit the doors 14 to fall by gravity or by the weight of the dirt or other material thereon to an open position as shown in FIG. 14. The dirt or cutaway material is thus dumped from the reamer of FIGS. l0l4. The reamer is then in a position for again underreaming the same hole to a greater extent or for underreaming some other hole.

In FIG. 16, a modified latching arrangement for the drop plates 14 is illustrated. With such construction, the curved stop or latch plate 256 has its lower edge 256a formed so that it contacts the lower surface of the left drop door 14 (FIG. 15). Such contact in the closed position of the rods or links 50 holds the left drop door 14 in the closed or substantially horizontal position. Similarly, the other rod or link 50 has a curved latch plate 254 which has a similar stop or latch surface 254a which engages the lower surface of the right drop door 14 in FIG. 15. Such construction of FIG. 15 functions in the same way as explained in connection with FIGS. 10-14 to hold the drop plates 14 in their closed position until they hit the bottom of a hole which is to be underreamed. When it is des red to dump the contents of the material which is confined within the reamer after a reaming operation, the downward swinging of the rods 50 turn or rotate the stop surfaces 256a and 254a around the hinge pin 16 so that such doors 14 can fall by gravity or by the weight of the cut-away material thereon to dump such material from the reamer.

It will thus be seen that the invention, as described above is in several forms, provides an underreamer by which holes may be formed with enlarged portions shaped for the construction of concrete foundations of the underreamed type in which the foundation has a vertical wall at its lower portion to provide improved strength and resistance to breakage of the concrete in the enlarged portion of the hole.

The invention has been disclosed in connection with a specific embodiment of the same, but it will be understood that this is intended by way of illustration only, and that numerous modifications can be made in the construction and arrangement of the various parts, without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A reamer for enlarging an earth bore, comprising a hollow body adapted to be inserted in the bore, said body having a substantially longitudinally extending portion formed with a side opening, a cutter member adapted to be removably positioned in said side opening, a crosshead in said body having a pivotal connection with the upper end of said cutter member for permitting said cutter member to swing outwardly relative to said cross-head and said body, and a rotatable means longitudinally movable relative to said cross-head and connected to said cutter member below said cross-head and operable from the ground level above the bore for imparting an outward movement to said cutter member to cause same to swing about its pivotal connection with the cross-head to engage the wall of the bore at an angle and to impart rotation to said cutter member as said cutter member is moved outwardly whereby a downwardly and outwardly sloping wall is formed in the bore which is increasingly enlarged as the cutter member is rotated and moved outwardly.

2. A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the bore, said body being tubular and having a longitudinal opening therein, an operating shaft extending into said opening, a cutter member having a cutter blade thereon for cutting engagement with the wall of the bore, means connecting said shaft to said cutter member at a longitudinally intermediate portion of said cutter member for imparting lateral movement directly to said cutter member to move said cutter member outwardly and inwardly relative to said body upon a longitudinal movement of said shaft relative to said body, a cross-head having a pivotal connection with the upper end of said cutter member for the swinging of said cutter member relative to said cross-head as the lateral movement is imparted to said cutter member, means for preventing lateral movement of the upper end of said cutter member as the lateral movement is imparted to the cutter member for thereby causing said cutter member to swing back and forth at an angle with respect to the body, and means for rotating said operating shaft to impart rotation to said cutter member as it is caused to swing outwardly at an angle, whereby an enlarged hole is formed in said bore.

3. A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the bore, said body being tubular and having a longitudinal opening therein, an operating shaft extending into said opening, a cutter member having a cutter blade thereon for cutting engagement with the wall of the bore, means connecting said shaft to approximately the longitudinal mid-portion of said cutter member for transmitting lateral movement to said cutter member to move said cutter member outwardly and inwardly relative to said body upon a longitudinal movement of said shaft relative to said body, a cross-head having a pivotal connection with the upper 7 end of said cutter member for the swinging of said cutter member relative to said cross-head as the lateral movement is imparted to said cutter member, means to prevent lateral movement of said cross-head as the lateral movement is imparted to said cutter member so that the upper end of said cutter member is prevented from moving laterally whereby such cutter member is caused to move outwardly at an increasing inclination in a downward and outward direction when said shaft is forced downwardly relative to said body, and means for rotating said operating shaft to impart rotation to said cutter member as it is caused to swing outwardly at an angle, whereby an enlarged hole is formed in' said bore.

4. A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the bore, a first cutter member having a cutter blade thereon for engagement with the wall of said here, a rotatable means for imparting an outward movement to said first cutter member when said body is lowered into the bore, means to prevent the upper end of said first cutter member from moving laterally while permitting same to move vertically in the bore as said outward force is applied thereto, and means to prevent the lower end of said first cutter memher from moving vertically while permitting same to move laterally as said outward force is applied thereto, whereby said first cutter member is moved outwardly at an angle relative to the wall of said bore and into engagement therewith for cutting said wall at an angle to enlarge same upon a rotation of said first cutter member, a second cutter member also having a cutter blade thereon for engagement with the wall of the bore, means pivotally connecting said second cutter member to the lower end of said first cutter member, and means for maintaining said second cutter member in a substantially vertical position in all positions of said first cutter member, whereby an annular substantially vertical wall is formed with said second cutter member below the enlargement provided by the cutting action of said first cutter member.

5. A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the bore, said body being tubular and having a longitudinal opening, an operating shaft extending through said opening, a first cutter member having a cutter blade thereon for cutting engagement with the wall of the bore, means connecting said shaft to said first cutter member for imparting lateral movement directly to said first cutter member to move said first cutter member outwardly and inwardly relative to said body upon a longitudinal movement of said shaft relative to said body, means for preventing lateral movement of the upper end of said first cutter member as the lateral movement is imparted to the first cutter member for thereby causing said first cutter member to swing back and forth at an angle with respect to the body, means for rotating said operating shaft to impart rotation to said first cutter member as it is caused to swing outwardly at an angle, whereby an enlarged hole is formed in said bore, a second cutter member also having a cutter blade thereon for engagement with the wall of the bore, means pivotally connecting said second cutter member to the lower end of said first cutter member, and means for maintaining said second cutter member in a substantially vertical position in all positions of said first cutter member, whereby an annular substantially vertical wall is formed with said second cutter member below the enlargement provided by the cutting action of said first cutter member.

6. A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the bore, said body being tubular and having a longitudinal opening, an operating shaft extending through said opening, a first cutter member having a cutter blade thereon for cutting engagement with the wall of the bore, means connecting said shaft to said first cutter member for imparting lateral movement directly to said first cutter member to move said first cutter member outwardly and inwardly relative to said body upon a longitudinal movement of said shaft relative to said body, a cross-head having a pivotal connection with the upper end of said first cutter member for the swinging of said first cutter member relative to said cross-head as the lateral movement is imparted to said first cutter member, means to prevent lateral movement of said cross-head as the lateral movement is imparted to said first cutter member so that the upper end of said first cutter member is prevented from moving laterally whereby such first cutter member is caused to move outwardly at an increasing inclination in a down- Ward and outward direction when said shaft is forced downwardly relative to said body, means for rotating said operating shaft to impart rotation to said first cutter member as it is caused to swing outwardly at an angle, whereby an enlarged hole is formed in said bore, a second cutter member also having a cutter blade thereon for engagement with the wall of the bore, means pivotally connecting said second cutter member to the lower end of said first cutter member, and means for maintaining said second cutter member in a substantially vertical position in all positions of said first cutter member, whereby an annular substantially vertical wall is formed with said second cutter member below the enlargement provided by the cutting action of said first cutter member.

7. A reamer for enlarging the lower end of an earth bore, comprising a body adapted to be lowered into the bore, said body having stop means at its lower end for engaging the bottom of the bore to position the body in the bore for resisting downward movement thereof, a cutter member having a cutter blade thereon for cutting engagement with the wall of the bore, an operating shaft, connection means connecting said shaft to a longitudinally intermediate portion of said cutter member for imposing Weight on said cutter, means connecting said step means on the lower end of said body with said cutter member to prevent downward movement of said cutter member upon the application of the downward movement of said shaft to said cutter member through said connection means, whereby the cutter member is forced to move laterally outwardly as said shaft is moved downwardly, and said shaft being rotatable as said shaft is forced downwardly and said cutter member is forced outwardly,

13 whereby an enlarged underreamed area is provided in the bore.

8. The structure set forth in claim 7, wherein said body has an upper stop surface, and means on the upper end of said cutter member for contacting said upper stop surface to limit the upward movement of the cutter member relative to said body as it is moved inwardly to a retracted position for lowering and removal from the bore.

9. The structure set forth in claim 7, including a cross-head, a pivotal connection between said cross-head and the upper end of said cutter member, and means to prevent said cross-head from moving laterally while it moves vertically with the cutter member, whereby the cutter member is caused to pivot about said pivotal connection as it is moved outwardly by the lowering of said shaft.

10. The structure set forth in claim 9, including a cross-head, means pivotally connecting said cross-head to said cutter member, a drive member on said cross-head, said drive member and shaft having co-acting surfaces so that the rotation of the shaft is imparted to the drive member.

11. The structure set forth in claim 7, including a drive member operatively connected with said cutter member, said drive member and shaft having co-acting surfaces for imparting the rotation of the shaft to said drive member.

12. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, said body having a substantially longitudinally extending portion formed with side openings, a crosshead, closures pivotally carried by said cross-head for vertical swinging movement into and out of closing relation to said openings, cutters on said closures, means for swinging the closures outwardly about their pivotal connection to said cross-head, each of said closures having a vertically disposed lower end portion hingedly connected thereto, each of said lower end portions having cutter means therewith for engaging the earth bore, and means for holding said portions in vertical positions in all positions of said closures for cutting a substantially vertical bore portion in the earth bore with said end portions.

13. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, said body having a substantially longitudinally extending portion formed with side openings, a crosshead, closures pivotally carried by said cross-head for vertical swinging movement into and out of closing relation to said openings, means for swinging the closures outwardly about their pivotal connection to said crosshead, said closures having longitudinally spaced openings therein, the openings of one of said closures being offset longitudinally thereof with respect to the openings of another of said closures, and cutting elements carried by said closures and extending outwardly thereof through said openings.

14. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, an operating shaft extending into said hollow body, said body having a substantially longitudinally extending portion formed with side openings, a cross-head, closures pivotally carried by said cross-head for vertical swinging movement into and out of closing relation to said openings, means connecting said shaft to said closures for imparting rotation from said shaft to said closures, cutters on said closures, means for swinging the closures outwardly about the pivotal connection to said cross-head, vertically swingable doors forming the bottom of said body, hinge means for connecting said doors together, and means for holding said doors in the closed position when said closures are in a closed position, said last-named means being releasable for permitting said doors to swing downwardly by gravity to an open position when said doors are unsupported therebelow and when said body is held against downward movement as said closures are swung outwardly for thereby effecting a dumping of any cuttings on said doors.

15. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, said body having a substantially longitudinally extending portion formed with side openings, a cross-head, closures pivotally carried by said cross-head for vertical swinging movement into and out of closing relation to said openings, cutters on said closures, means for swinging the closures outwardly about their pivotal connection to said cross-head, scoop elements pivotally connected to the body for horizontal swinging movement into and out of said body through said side openings, and means on said closures for contacting said elements to prevent said elements from moving outwardly when said closures are in their closed or retracted position.

16. A reamer for enlarging the lower ends of earth bores, comprising a hollow cylindrical body adapted to be inserted in a bore and having opposite side openings, a vertically disposed operating shaft extending into the upper end of the body and movable vertically therein, means on the body engageable with the shaft to cause the body to rotate with the shaft, a cross-head, closures hingedly connected at their upper ends to said cross-head for vertical swinging movement into and out of closing relation to said openings, cutters on said closures, means for swinging said closures outwardly about their pivotal connection to said cross-head, means connected to said closures and said shaft and operable upon downward movement of the shaft relative to the body to move said closures toward open position and upon upward movement of said shaft relative to said body to move said closures toward closed positon, scoop elements hingedly connected to said body inwardly of said openings for horizontal swinging movement inwardly and outwardly through said openings, and means connected to said closures and said elements and operable upon opening movement of said closures to move said elements outwardly into position for scooping into said body the cuttings made by the engagement of the cutters on the closures with the earth bore.

17 A reamer for enlarging an earth bore, comprising a body adapted to be lowered into the earth bore, a cutter member adapted to engage the earth bore, a cross-head in said body having a pivotal connection with the upper end of said cutter member for permitting said cutter member to swing outwardly relative to said cross-head and said body, an operating shaft extending into said body and through said cross-head and movable relative to said crosshead and said body, means connecting said operating shaft to said cutter member below said cross-head for imparting an outward movement to said cutter member to cause same to swing about its pivotal connection with said crosshead to engage the wall of the earth bore at an angle, and said operating shaft being rotatable to impart rotation thereto and to the cutter member for forming a downwardly and outwardly sloping wall in the earth bore which is increasingly enlarged as the cutter member is rotated and moved outwardly.

18. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, said body having a substantially longitudinally extending portion formed with side openings, a vertically movable cross-head in the body, closure means pivotally connected to the cross-head for movement into and out of closing relation to said openings, each of said closures having spaced openings therein, cutting elements carried by the closures and having cutting edges disposed outwardly of the closure openings, said body including a drive member having an opening therethrough formed by a plurality of substantially longitudinally extending surfaces, a vertically movable operating member extending through said opening of said drive member and having surfaces engaging the longitudinal surfaces of said drive member to rotate the body upon rotation of the member, and

1 5 means connecting said closure means and said operating member below the upper ends of said closure means for transmitting downward movement of said member to said closure means to move said closure means toward open position.

19. A reamer for enlarging the lower ends of earth bores, comprising a hollow body adapted to be inserted in a bore, said body having a substantially longitudinally extending portion formed with side openings, a vertically movable cross-head in the body, closures disposed opposite the openings and pivotally connected at their upper ends to the cross-head for vertical swinging movement toward and away from the body, each of said closures having spaced openings therein, cutting elements carried by the closures and extending outwardly thereof beyond said closure openings and having cutting edges at their outer ends, said body including a drive member having an opening therethrough formed by a plurality of substantially longitudinally extending surfaces, a vertically disposed operating shaft extending through said opening of said drive member and movable vertically relative there-to, said shaft having surfaces thereon engageable with the longitudinal surfaces of said drive member with the body to rotate the body upon rotation of the shaft, and means pivotally connecting the closures to the shaft below the upper ends of the closures for transmitting downward movement of the shit to said closures to move said closures away from the body.

20. A reamer for enlarging an earth bore, comprising a hollow body, a cross-head in said body adapted to move longitudinally relative to said body a plurality of cutter members each having at least one cutter blade thereon for cutting the wall of the bore to an enlarged size in a selected area, hinge means connecting the upper ends of said cutter members to said cross-head for permitting said cutter members to swing outwardly and inwardly relative to each other about said hinge means, rotatable drive means longitudinally slidable in said body relative to said cutter members and slidably connected thereto at the upper ends of said cutter members for rotating said cutter members upon a rotation of said drive means, means connecting said drive means to said cutter members below said'hinge means for applying an outward force to a portion of said cutter members below said hinge means for swinging said cutter members outwardly from a substantially vertical retracted position to cutting positions at constantly increasing angles of inclination with respect to the longitudinal axis of the bore, and said cutter members being rotatable as they are swung outwardly until said bore is enlarged to the desired size.

21. A reamer for enlarging an earth bore, comprising a plurality of cutter members each having at least one cutter blade thereon for cutting the wall of the bore to an enlarged size in a selected area, hinge means connecting the upper ends of said cutter members together for permitting said cutter members to swing outwardly and inwardly relative to each other about said hinge means, means connected to said cutter members below said hinge means for applying an outward force to a portion of said cutter members below said hinge means for swinging said cutter members outwardly from a substantially vertical retracted position to cutting positions at constantly increasing angles of inclination with respect to the longitudinal axis of the bore, said cutter members being rotatable as they are swung outwardly until said bore is enlarged to the desired size, an auxiliary cutter member on each of said cutter members, and means for maintaining said auxiliary cutter members substantially vertical throughout the entire outward travel of said cutter members whereby an annular portion with a substantially vertical wall is formed in the enlarged bore.

22. A reamer for enlarging an earth bore, comprising a plurality of cutter members each having at least one cutter blade thereon for cutting the wall of the bore to an enlarged size in a selected area, hinge means connecting the upper ends of said cutter members together for permitting said cutter members to swing outwardly and inwardly relative to each other about said hinge means, means connected to said cutter members below said hinge means for applying an outward force to a portion of said cutter members below said hinge means for swinging said cutter members outwardly from a substantially vertical retracted position to cutting positions at constantly increasing angles of inclination with respect to the longi tudinal axis of the bore, said cutter members being rotatable as they are swung outwardly until said bore is enlarged to the desired size, and adjustable stop means for limiting the extent of the outward movement of the cutter members to limit the size of the enlarged portion of the bore.

23. A reamer for enlarging an earth bore, comprising a plurality of cutter members each having at least one cutter blade thereon for cutting the wall of the bore to an enlarged size in a selected area, hinge means connecting the upper ends of said cutter members together for permitting said cutter members to swing outwardly and inwardly relative to each other about said hinge means, means connected to said cutter members below said hinge means for applying an outward force to a portion of said cutter members below said hinge means for swinging said cutter members outwardly from a substantially vertical retracted position to cutting positions at constantly in creasing angles of inclination with respect to the longitudinal axis of the bore, said cutter members being rotatable as they are swung outwardly until said bore is enlarged to the desired size, drop doors adapted to he positioned on the bottom of the bore during the underreaming of the bore for receiving the dirt, rocks or other material which is cut away from the bore during the enlargement thereof, hinge means connecting said drop doors together, latch means for retaining said doors in a substantially lateral closed position during the withdrawal of the reamer from the bore, and means for simultaneously releasing said latch means and for swinging said doors outwardly to an open position when said reamer is removed from said bore for dumping the cut-away material therefrom.

References Cited in the file of this patent V UNITED STATES PATENTS 465,048 Pech Dec. 15, 1891 1,236,940 Husselmann Aug. 14, 1917 1,257,561 Weber Feb. 26, 1918 2,320,610 Kandle June 1, 1943 2,450,223 Barbour Sept. 28, 1948 2,631,013 Darin Mar. 10, 1953 2,697,586 Talley Dec. 21, 1954 2,719,700 Kammerer Oct. 4, 1955 2,743,904 Scott May 1, 1956 2.799,477 Kammerer July 16, 1957 

